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Every Amiga depends heavily on the Kickstart ROM chips on the
motherboard. The A3000 is no exception.
Types of ROMs
-Often referred to as softboot ROMs, these were originally
shipped with early model A3000's. They automatically
find a bootable drive named WB_2.x:, and looks for a
file called kickstart in the devs: directory of the system boot
This is a specially encoded KickStart file.
You can put all sorts of ROM images for the 1.4 chip
to boot, including WB2.03, WB2.04, and also, WB3.1.
Once it finds the file, it reallocates memory with the MMU,
and effectivly turns 512K of FAST RAM into a ROM.
This is good because it's fast and easily upgradable.
However, it will not work with 040 or 060 CPUs, as the MMU
utilization is different.
2.042.04 Kickstart Hard ROM
-These shipped with many machines. They don't use 512K
of FAST RAM, but instead, have 2.04 burned in them.
These will support 2.04, 2.05 and 2.1 software, plus
040 CPUs. They do cause some incompatibilities with
the A3640 accelerator, with Page Mode RAM.
3.13.1 Kickstart Hard ROM
-Distributed by VillageTronic and other licensees, or
copied by others, the 40.68 ROM is the latest revision.
It supports RTG, 040 and 060 CPUs. The 40.70 ROM,
is not as widely distributed. Some have had troubles
with tape drives and this revision.
See also, A3640-Issues
The 3.0 ROM from A1200 and A4000 systems can't be used: Instead of
the 33C93 based driver code, the 3.0 build for A1200/4000 has code for IDE
devices instead through the Gayle chip.
ROMs from A500 and A2000 systems can't be used either, they're a
single chip (at least for most models of these systems) and again, do not
contain code for A3000 specific fetaures.
Extra ROM Silkscreens and Reversed Silkscreens
There are extra silkscreen positions for a second pair of ROM
chips on the A3000 motherboard. They are for different types of ROM,
apparently left in for developers.
The silkscreened printing on the motherboard may indicate ROM0 and
ROM1 incorrectly. Reversing them won't damage them.
Some A3000 owners have noted that new 3.1 ROM chips can't be run at
25 Mhz. Set the ROM speed at 16 Mhz with jumpers J150 and J151.
Some A3000 users have found that new 3.1 ROM chips cause SCSI
instabilities by draining power from termination power.